Palmitoleic acid (also known as (Z)-9-hexadecanoic acid, cis-palmitoleic acid, 9-cis-palmitoleic acid, hexadec-9-enoic acid and C16:1) is an omega-7 monosaturated fatty acid with the chemical formula CH3(CH2)5CH═CH(CH2)7COOH. Palmitoleic acid also exists in a trans form (known as trans-palmitoleic acid, 9-trans-palmitoleic acid or (E)-9-hexadecanoic acid, which demonstrates improved thermodynamic stability over the cis isomer. Trans-palmitoleic acid is found in certain dairy products. The conversion from cis- to trans-palmitoleic acid can be achieved thermally, chemically or enzymatically. Palmitoleic acid is present in variety of vegetable oils, animal fats and marine oils in small quantities. Two plant sources having high concentrations of palmitoleic acid are sea buckthorn (Hippophae rhamnoids), which belongs to the Elaeagnacae family and Rosales order (a taxonomic order which includes strawberries, blackberries, apples, pears, peaches, apricots, and almonds) and macadamia nut oil (Macadamia integrifolia), which is native to Australia. Palmitoleic acid concentration of sea buckthorn is about 40% and macadamia oil contains about 20%. Another source of palmitoleic acid is mink oil, which contains about 15% palmitoleic acid. All these sources have limited availability and are premium sources. The plant sources are being used as food supplements (sea buckthorn fruit is used as “superfood”) or premium food ingredient (macadamia nuts are used in chocolate and other high value foods) or in cosmetics (mink oil). Palmitoleic acid is biosynthesized from palmitic acid by the action of the enzyme delta-9 desaturase.
Palmitoleic acid has shown utility in medical applications. For example, palmitoleic acid has been shown to improve hyperglycemia (high glucose concentration in blood) and hypertriglyceridemia and increase sensitivity, by suppressing proinflammatory gene expressions and improving hepatic lipid metabolism in diabetic mice. Yang, Z-H. et al. “Chronic administration of palmitoleic acid reduces insulin resistance and hepatic lipid accumulation in KK-Ay Mice with genetic type 2 diabetes” Lipid Health Disease 2011, 10, 120.
Palmitoleic acid has also been shown to prevent beta-cell apoptosis induced by glucose or saturated fatty acids (beta-cells or pancreas secrete insulin and their programmed death or apoptosis leads to type-2 diabetes). Morgan, N. G.; Dhayal, S. “Unsaturated fatty acids as cytoprotective agents in the pancreatic β-cell” Prostaglandins Leukot. Essent. Fatty Acids 2010, 82, 231-236; Morgan, N. G. et al. “The cytoprotective actions of long-chain mono-unsaturated fatty acids in pancreatic β-cells” Biochem. Soc. Trans. 2008, 36, 905-908.
Palmitoleic acid-rich diets have also been reported to improve circulating lipid profile, resulting in reduced total and LDL cholesterol. Matthan, N. R. et al. “Effects of dietary palmitoleic acid on plasma lipoprotein profile and aortic cholesterol accumulation are similar to those of other unsaturated fatty acids in the F1B Golden Syrian Hamster” J. Nutr. 2009, 139 (2), 215-221; Griel, A. E. et al. “A macadamia nut-rich diet reduces total and LDL-cholesterol in mildly hypercholesterolemic men and women” J. Nutr. 2008, 138 (4), 761-767; Garg, M. L. et al. “Macadamia nut consumption lowers plasma total and LDL cholesterol levels in hypercholesterolemic men” J. Nutr. 2003, 133 (4), 1060-1063.
Trans-palmitoleic acid concentration in blood levels have been independently associated with higher HDL-cholesterol levels, lower triglyceride levels, and a lower total-cholesterol/HDL-cholesterol ratio. In addition, trans-palmitoleic acid has also been associated with less insulin resistance and a lower risk of new-onset diabetes mellitus. Mozaffarian, D. et al. “Trans-palmitoleic acid, metabolic risk factors, and new-onset diabetes in U.S. adults: a cohort study: Ann. Intern. Med. 2010, 153 (12), 790-799.
In addition, palmitoleic acid has been shown to be useful in skin care and cosmetic applications as a highly effective antioxidant. Research has suggested that palmitoleic acid may be involved in the cell rejuvenation and healing process, particularly in dry and/or mature skin. Palmitoleic acid supports cell regeneration and can help heal burns and wounds, and reduces dermatitis and eczema. It also offers some protection form the harmful effects of the sun. When applied directly to the skin, palmitoleic acid can increase triglyceride concentration in the lipid barrier of the skin, one of the naturally occurring stratum corneum lipid components, consequently enhancing the protective nature of the stratum corneum.
As more beneficial applications for palmitoleic acid are discovered, the demand for palmitoleic acid may increase beyond the limited supply readily available from sea buckthorn, macadamia nut oil, and mink oil. Alternative sources for palmitoleic acid in which a high concentration of palmitoleic acid may be readily obtained year round at lower costs could provide a new supply source. With the recognized benefits of palmitoleic acid, there is a need in the art for compositions with a concentration high in omega-7 fatty acids and an efficient method of obtaining the omega-7 fatty acids from a readily available source.